Brian Eno and Peter Schmidt Oblique Strategies Deck 2001 Fifth Edition

Oblique Strategies (subtitled Over One Hundred Worthwhile Dilemmas) is a card-based method for promoting creativity jointly created by musician/artist Brian Eno and multimedia artist Peter Schmidt, first published in 1975. Physically, it takes the form of a deck of 7-by-9-centimetre (2.8 in × 3.5 in) printed cards in a black box.[1][2][3] Each card offers a challenging constraint intended to help artists (particularly musicians) break creative blocks by encouraging lateral thinking.

Each card contains a gnomic suggestion, aphorism or remark which can be used to break a deadlock or dilemma situation. A few are specific to music composition; others are more general. 

From the introduction to the 2001 edition:

These cards evolved from separate observations of the principles underlying what we were doing. Sometimes they were recognised in retrospect (intellect catching up with intuition), sometimes they were identified as they were happening, sometimes they were formulated. They can be used as a pack, or by drawing a single card from the shuffled pack when a dilemma occurs in a working situation. In this case the card is trusted even if its appropriateness is quite unclear...

Musicians inspired by Oblique Strategies include the British band Coldplay, said to have used the cards when recording their 2008 Brian Eno-produced album Viva la Vida or Death and All His Friends and French band Phoenix, who used the cards when recording their 2009 album Wolfgang Amadeus Phoenix.

German musician/composer Blixa Bargeld has a similar navigation system, called Dave. In response to their song "Brian Eno", from their album Congratulations, MGMT has said they had a deck of Oblique Strategies in the studio, but they "don't know if [they] used them correctly." The band Bauhaus have used the cards for the composition of their songs. The B-52's used them in the studio when recording their first album.

They were most famously used by Eno during the recording of David Bowie's Berlin triptych of albums (Low, "Heroes", Lodger). Stories suggest they were used during the recording of instrumentals on "Heroes" such as "Sense of Doubt" and were used more extensively on Lodger ("Fantastic Voyage", "Boys Keep Swinging", "Red Money"). They were used again on Bowie's 1995 album Outside, which Eno was involved with as a writer, producer and musician. Carlos Alomar, who worked with Eno and Bowie on all these albums, was a fan of using the cards, later saying "at the Center for Performing Arts at the Stevens Institute of Technology, where I teach, on the wall are Brian Eno’s Oblique Strategies cards. And when my students get a mental block, I immediately direct them to that wall."

The cards are in Excellent, near mint condition